Continuous Galerkin Spectral Element Implementation for Interface Capturing Simulation of Glass Melters in Nek5000

This work introduces a novel spectral element, continuous Galerkin, based interface capturing approach implemented in Nek5000. We employ the conservative level-set method for implicity capturing the interface, while the interface normals are pre-conditioned using the traditional level-set field representation. To preclude spurious currents during the transport and re-initialization/re-distancing of the level-set field, a spectral vanishing viscosity method based artificial diffusion term is employed which enables smooth advancement of the solution while adding minimal and highly localized dissipation effects. Challenging canonical problems are presented herein to demonstrate the excellent transport properties of the overall formulation. Further, the transport algorithm is adopted for the simulation of canonical incompressible two-phase problems, viz., the Rayleigh-Taylor instability and dam break problem, the latter involving high-density and viscosity ratio, to serve as validation exercises for the coupled level-set and flow solver in Nek5000. Finally, the numerical method is employed for the simulation of a bubble sparging problem with subsequent application intent for simulation of interface transport in waste glass melters for removal of radioactive waste.